Watch asteroid fly-by live online Friday

An asteroid is expected to pass closely by Earth on Friday, as… (NASA/JPL-CalTech )

February 15, 2013|By Scott Dance, The Baltimore Sun

A 150-foot wide asteroid is expected to pass closely by Earth on Friday, and though it will be difficult to see in skies over the U.S., the fly-by will be broadcast online.

Backyard astronomers on the other side of the world will be able to see the asteroid, known as 2012 DA14, as the object makes its closest pass by Earth. But by the time it comes into view over Baltimore's skies, it will have moved far enough away that it will be tougher to see.

"It will brighten only to magnitude 7.5, too faint to be seen with the naked eye, but easily visible with a good set of binoculars or a small telescope. The best viewing location for the closest approach will be Indonesia, from which the asteroid will be seen to move at a rate of almost 1 degree per minute against the star background. Eastern Europe, Asia and Australia are also well situated to see the asteroid around its closest approach. But by the time Earth rotates enough for observers in the continental United States to have a chance to see the asteroid, it will have receded and faded to about the 11th magnitude."

The asteroid is expected to pass about 17,000 miles from Earth, at its closest, about 1/13th of the distance between the moon and Earth. It is expected to reach that distance at 2:24 p.m. EST. That is the closest pass of an asteroid of that size that astronomers detected in advance.

At that altitude, there is a chance the asteroid could strike some satellites, though it will be too far to affect most satellites as well as the International Space Station, according to NASA.